首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19520篇
  免费   352篇
  国内免费   1篇
管理学   2821篇
民族学   69篇
人才学   1篇
人口学   1897篇
丛书文集   77篇
教育普及   2篇
理论方法论   1735篇
现状及发展   1篇
综合类   260篇
社会学   9431篇
统计学   3579篇
  2021年   117篇
  2020年   283篇
  2019年   388篇
  2018年   455篇
  2017年   609篇
  2016年   484篇
  2015年   362篇
  2014年   472篇
  2013年   3007篇
  2012年   645篇
  2011年   619篇
  2010年   455篇
  2009年   379篇
  2008年   446篇
  2007年   470篇
  2006年   462篇
  2005年   446篇
  2004年   414篇
  2003年   386篇
  2002年   421篇
  2001年   525篇
  2000年   533篇
  1999年   463篇
  1998年   343篇
  1997年   313篇
  1996年   325篇
  1995年   308篇
  1994年   286篇
  1993年   289篇
  1992年   345篇
  1991年   320篇
  1990年   286篇
  1989年   294篇
  1988年   289篇
  1987年   253篇
  1986年   243篇
  1985年   278篇
  1984年   269篇
  1983年   252篇
  1982年   216篇
  1981年   180篇
  1980年   164篇
  1979年   195篇
  1978年   179篇
  1977年   159篇
  1976年   134篇
  1975年   158篇
  1974年   118篇
  1973年   115篇
  1972年   94篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
This study examined the bidirectional relations between authoritative parenting and adolescents’ prosocial behavior over a 1‐year time period. Data were taken from Time 2 and 3 of the Flourishing Families Project, and included reports from 319 two‐parent families with an adolescent child (M age of child at Time 2 = 12.34, SD = 1.06, 52% girls). Cross‐lag analyses supported bidirectional relations between parenting and prosocial behavior with particular emphasis on the role of the adolescents’ prosocial behavior on subsequent parenting. Results also varied as a function of the reporter. Discussion focuses on the implications for understanding the multifaceted nature of prosocial development in adolescence.  相似文献   
972.
973.
974.
975.
976.
977.
In some occupations pushing forces are frequent when performed on horizontal ground and are standardized (ISO 2002). In special cases employees are obliged to grow container on slopes and the strains are poorly investigated. The objective of this work is to measure forces required to push garbage container on horizontal and inclined at 0, 4, 11 and 16 % grounds. Sudden and significant increases in heart rate reflect the possible risk of heart overload in long displacements. This study proposes realistic limits and provides a simple and protective tool for a group of employees without distinction of age or gender. These limits can even be reduced to a quasi-linear model where push 200 kg is the maximum for 0% slope and 60 kg for 10% slope.  相似文献   
978.
In order to implement preventive programs to prevent back pain in nurses, assessments of the degree of passivity and mobility of patients is imperative. After all, the load in health care ergonomics, is often the patient. The degree of cooperation or resistance determines the load on the back for the nurses and the necessity of the use of lifting devices like patient lifters or sliding sheets. These assessments must be done in both a practical and a reliable way. For this purpose a 3-category and a 5- category system to assess the degree of patient mobility and passivity was developed and tested. The results are presented on the poster.  相似文献   
979.
In hospitals many horizontal transfers (from stretcher to bed etc.) are performed from the moment a patient is admitted (f.e. with an ambulance) through examination departments all the way to the wards. These transfers can be very strenuous and solutions may be to use a special lifting device that accompanies the patient on this route: a stretcher sling This is a specially designed disposable lifting sling for horizontal transfers and repositioning, the sling can easily be connected to a ceiling or mobile lift. The ambulance service, two hospitals and a manufacturer decided to study the effects. The stretcher sling travels with the patient. Does this provide an ergonomically sound solution and is this an effective and efficient solution? The results were positive, but a behavioral change was also necessary.  相似文献   
980.
The operating microscopes may be a significant cause of fatigue and discomfort in surgeons. The need for the microscope to be placed over the operating field forces surgeons to remain at the microscope's eyepieces at an uncomfortable posture for the entirety of the surgery. This study compared the effects on microsurgical task performance for four visualization methods: a monocular microscope, a binocular microscope, a three-dimensional (3D) flat-panel television display and a two-dimensional (2D) flat-panel television display. Eleven subjects each performed two microsurgical tasks and their performance was documented by video camera. The statistical analysis performed indicated utilization of the microscope as a visualization method increased subject performance. No significant difference in performance between the 2D and stereoscopic visualization methods.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号